Precoat resin dispersion for tufted carpets

ABSTRACT

Disclosed is a precoat resin dispersion having a solids content from about 63% to about 69% comprising (1) at least one resin having a Ring and Ball softening point from about 60° C. to about 100° C. in an aqueous dispersion having a solids content from about 53% to about 58%; (2) at least one water-soluble polymer; (3) at least one cationic resin; and (4) water. The precoat resin dispersion is useful in the manufacture of tufted carpets, especially carpets manufactured with carboxylated latices as a backcoat.

This application is a division of application Ser. No. 627,705, filed7/3/84.

This invention relates to chemical compositions. Particularly, thisinvention relates to novel precoat resin dispersions useful in themanufacture of tufted textile articles, such as, tufted carpets.

Tufted textile articles are made by inserting a plurality of vertical,reciprocating needles threaded with yarn into a moving primary backingfabric to form tufts of yarn. Loopers or hooks, which work in a timedrelationship with the stroke of the needles, are located below theprimary backing so that the loopers are positioned just above the needleeye when the needles are at the lowest point in their downward stroke.When the needles reach the lowest point in the downward stroke, the yarnis picked up from the needles by the loopers and held momentarily. Loopsor tufts of yarn are formed as the needles are drawn back through thebacking fabric. This process is repeated when the previously formedloops are moved away from the loopers as the backing fabric is advanced.

The loops can be cut during the tufting process to form a cut pile asopposed to a loop pile construction. If a cut pile is desired, a looperand knife combination is used in the tufting process.

Additional information on the manufacture of tufted articles may befound in Rose, Stanley H., "Tufted Materials", Man-Made TextileEncyclopedia, Chap. IX, Textile Book Publishers, Inc., (1959).

When the tufted article is a carpet, the primary backing fabric istypically a woven or nonwoven fabric made of one or more of natural andsynthetic fibers, such as jute, wool, rayon, polyamides, polyesters,polypropylene and polyethylene, or of films of synthetic materials, suchas polypropylene, polyethylene, and copolymers thereof.

The tufts of yarn inserted during the tufting process are usually heldin place by the untwisting action of the yarn in combination with theshrinkage of the backing fabric. However, when the article is a tuftedcarpet, the back of the backing fabric may be coated with a backcoatmaterial, such as a latex or emulsion of natural or synthetic rubbers orsynthetic resins, or a hot melt adhesive, to assist in locking oranchoring the tufts to the backing material, to improve the dimensionalstability of the tufted carpet, to make the carpet more durable and toprovide skid and slip resistance.

Generally, the tufted carpet is further stabilized by laminating asecondary backing, such as jute, woven or nonwoven fabrics made frompolypropylene, polyethylene, and copolymers thereof, to the tuftedcarpet.

Carpets bonded with a synthetic rubber or synthetic resin latexgenerally do not employ precoat compositions, such as precoat resindispersions, in their manufacture. When precoat compositions are used,they are applied to the backside of the primary backing in an amountsufficient to penetrate the individual tufts of yarn thereby increasingthe resistance of the tufts to pull-out, known as tuft-bond strength orpile-bond strength, and enhancing the bonding of the primary backingfabric to the backcoating material. The amount of precoat necessary topenetrate the individual tufts will vary depending on the carpet yarndensity and the efficacy of the precoat.

Up until this point, the use of a latex, wherein the resin has amultiplicity of carboxyl groups, such as a carboxylatedstyrene-butadiene latex, together with a cationic resin as thecrosslinking agent, particularly polyamide-epichlorohydrin resins, havefailed for one reason or another. Basically the mixtures of carboxylatedlatices and cationic resin have such a low shelf life that the mixturepartially or completely crosslinks in its shipping container before itcan even be brought into close proximity to let alone actual contactwith, the tufts on the backside of the tufted primary backing.

A precoat resin dispersion has now been found which improves thetuft-bond strength, narrows the statistical variation of tuft bondvalues and increases the stiffness and durability of carpets backcoatedwith carboxylated rubber latices. The precoat resin dispersion of thisinvention allows the cationic resin crosslinking agent to penetrate totufts on the backside of the tufted primary backing prior to the coatingand penetration of the same tufts with a carboxylated latex. Hence, theprecoat resin dispersion of this invention when applied as a precoat inthe manufacture of tufted carpets eliminates the opportunity for anypremature crosslinking between the cationic resin crosslinking agent andthe carboxylated latex, i.e. any crosslinking other than at the site ofthe tuft on the backside of the primary backing fabric.

According to the present invention, a precoat resin dispersion having asolids content from about 63% to about 69% is provided comprising byweight (1) from about 93% to about 99% of a resin in an aqueousdispersion having from about 53% to about 58% solids content; (2) fromabout 0.5% to about 5%, based on the total water content of (1), of awater-soluble polymer; (3) from about 0.1% to about 2% of a cationicresin, based on the total solids content of (1); and (4) optionally,sufficient water so that the solids content of the precoat resindispersion is from about 63% to about 69%. Preferably the precoat resindispersion of this invention has a solids content from about 64% toabout 67% and comprises from about 94% to 97% of component (1) with thesolids content of component (1) being from about 54% to 56 %; from 1.5%to about 2.5% of component (2); and from about 0.5 to 1.5% of component(3).

Any conventional method for preparing resin dispersions may be used toprepare the aqueous resin dispersion of component (1). Suitable methodsare taught in U.S. Pat. No. 3,582,464. Typically, when component (1) isa rosin-type resin, an aqueous solution of potassium hydroxide is addedto a molten resin in an amount aufficient to provide, by weight, fromabout 1% to 8% potassium resinate. Water, optionally containing anemulsifying agent, is then added in an amount sufficient to provide, byinversion, an oil-in-water type emulsion having a solids content fromabout 53% to about 58%. When component (1) is a hydrocarbon-type resin,an aqueous solution of potassium hydroxide is added to a molten resinadmixed with 1% to about 6% of a rosin or rosin ester in an amountsufficient to provide, by weight, from about 1% to about 6% potassiumresinate. Water is then added in an amount sufficient to provide, byinversion, an oil-in-water type emulsion having a solids content fromabout 53% to about 58%.

The precoat resin dispersion is particularly useful in the manufactureof carpets wherein carboxylated styrene-butadiene latices are used tocoat the tufted primary backing fabric prior to lamination with thesecondary backing fabrics. Generally the carboxylated styrene-butadienelatices contain up to 700 parts per hundred of a mineral filler.

All parts and percentages used in this disclosure and in the claims areby weight unless otherwise specified.

Component (1) of the precoat resin dispersion of this invention is atleast one resin having a Ring and Ball softening point from about 60° C.to about 100° C. in an aqueous dispersion of 53% to about 58% solids.Suitable resins include hydrocarbon resins prepared by polymerizing thecomponent mixture of a blend of a five carbon stream and a nine carbonstream from petroleum refining, commonly referred to as a C₅ -C₉ stream.Hence, the resins prepared from such a stream are commonly referred toas C₅ -C₉ resins. The components of a C₅ -C₉ stream are unsaturatedaliphatic and vinyl aromatic hydrocarbon compounds, both normal andbranched, in which the number of carbons generally does not exceed nine.Other suitable resins include hydrocarbon resins prepared bypolymerizing the monomer mixture of a five carbon component stream,known as a C₅ stream, from petroleum refining, the monomers beingprimarily unsaturated aliphatic. The resins prepared from a C₅ streamare commonly referred to as C₅ resins. The primary monomers present in aC₅ stream are di- and mono-olefins, both normal and branched, havingfive carbons and mono-olefins having six carbons. The preferredhydrocarbon resin is the C₅ resin.

In addition, polyterpene resins derived from alpha-pinene, beta-pinene,and monocyclic terpenes such as dipentene; and esters of rosin, such asthe methyl ester of rosin, the methyl ester of hydrogenated rosin, thetriethylene glycol ester of rosin, the triethylene glycol ester ofhydrogenated rosin, the diethylene glycol ester of rosin, the diethyleneglycol ester of hydrogenated rosin, the ethylene glycol ester of rosinand the ethylene glycol ester of hydrogenated rosin, the glycerol esterof rosin and the pentaerythritol ester of rosin can be used. Thepreferred ester of rosin is the glycerol ester of resin.

Component (2) of the precoat resin dispersion of this invention is atleast one water-soluble polymer having a molecular weight from about 100to about 10,000. Suitable polymers include polyacrylates, such aspolysodium acrylate, and cellulose derivatives, such ascarboxymethylcellulose, methylcellulose, hydroxyethylcellulose,hydroxypropylcellulose, methylhydroxyethylcellulose,methylhydroxypropylcellulose, carboxymethylhydroxyethylcellulose,hydroxypropylhydroxyethylcellulose, and hydrophobically modifiedhydroxyethylcellulose. Usually component (2) is added to component (1)as an aqueous dispersion of from about 4% to about 7% solids.

Component (3) of the precoat resin dispersion of this invention is atleast one cationic resin having a RVF Brookfield viscosity at 25° C. offrom about 50 centipoise (cps) to about 325 cps, preferably from about50 cps to about 100 cps. Preferably, the cationic resin is apolyamide-epichlorohydrin resin. The polyamide-epichlorohydrin resin canbe prepared by reacting a saturated aliphatic dicarboxylic acid with apolyalkylene amine to form a linear polyamide, and then reacting thepolyamide with epichlorohydrin. Suitable methods of preparation are setforth in U.S. Pat. Nos. 2,926,154 and 3,966,654. Typical polyamidesinclude copolymers of adipic acid and diethylenetriamine or adipic acidwith diethylenetriamine and ethylenediamine. Polyamide as used hereinincludes copolymers and terpolymers. Generally component (3) is added asan aqueous dispersion of from about 3% to about 7% solids.

In addition, small amounts of conventional additives, such asantioxidants, surfactants, flocculants, fillers and the like can beincluded in the precoat resin dispersions.

The following examples illustrate various aspects of this invention.They are not intended to limit the invention. Modifications of thespecific precoat resin dispersions, carpets prepared with the precoatresin dispersions and procedures of these examples can be made withoutdeparting from the spirit and scope of this invention.

EXAMPLE 1

This example illustrates a preferred specific embodiment of the precoatresin dispersion of this invention, and how to prepare it.

A mixing container affixed with a stirrer is charged with 92.5 g of theglycerol ester of a 50% hydrogenated rosin having a Ring and Ballsoftening point of 80° C. in an aqueous dispersion, the total solidscontent of the aqueous dispersion being approximately 55% and preparedas set forth herein above. Stirring is continued throughout alladditions until a precoat resin dispersion of this invention is formed.Two (2)%, based on the total water of the aqueous dispersion containingthe resin, of a polysodium acrylate, also in a dispersion which isdiluted with water to a 5.7% solids content, is added to the firstaqueous dispersion, followed by the addition of 1% of an (adipicacid-diethylenetriamine) polyamide-epichlorohydrin resin having aviscosity of 50 cps at 25° C. in a yet another aqueous dispersiondiluted with water to a 5.0% solids content, thereby providing a precoatresin dispersion of this invention.

EXAMPLE 2

This example illustrates another specific embodiment of the precoatresin dispersion this invention. The precoat resin dispersion isprepared according to the formulation and procedure of Example 1 exceptthat a 65% hydrogenated glycerol ester of rosin having a Ring and Ballsoftening point of 82° C. is used instead of the 50% hydrogenatedglycerol ester of rosin.

EXAMPLE 3

This example illustrates another embodiment of this invention. Theprecoat resin dispersion is prepared according to the formulation andprocedure of Example 1 except that an aliphatic hydrocarbon resin havinga Ring and Ball softening point of 85° C. is used instead of theglycerol ester of a 50% hydrogenated rosin.

EXAMPLE 4

This example illustrates another embodiment of this invention. Theprecoat resin dispersion is prepared according to the formulation andprocedure of Example 1 except that an aromatic hydrocarbon resin havinga Ring and Ball softening point of 95° C. is used instead of theglycerol ester of a 50% hydrogenated rosin.

EXAMPLE 5

This example illustrates another embodiment of this invention. Theprecoat resin dispersion is prepared according to the formulation andprocedure of Example 1 except that a 65% hydrogenated pentaerythritolester of rosin having a Ring and Ball softening point of 82° C. is usedinstead of the 50% hydrogenated rosin, except that 0.5% of thepolysodium acrylate is used instead of 2%, and except that apolyamide-epichlorohydrin resin having a RVF Brookfield viscosity of 325cps at 25° C., where the polyamide is terpolymer of adipic acid,diethylenetriamine, and ethylenediamine, is used instead of one having aviscosity of 50 cps at 25° C.

EXAMPLE 6

This example illustrates another embodiment of this invention. Theprecoat dispersion is prepared according to the procedure of Example 1using the formulation of Example 2 except that 0.5% of the polysodiumacrylate is used instead of 2%, and except that apolyamide-epichlorohydrin resin having a RVF Brookfield viscosity of 85cps at 25° C., where the polyamide is terpolymer of adipic acid,diethylenetriamine, and ethylenediamine, is used instead of one having aviscosity of 50 cps at 25° C.

EXAMPLE 7

This example illustrates another embodiment of this invention. Theprecoat resin dispersion is prepared according to the procedure ofExample 1 using the formulation of Example 2 except that 3% of ahydroxyethylcellulose is used instead of 2% of a polysodium acrylatedispersion.

EXAMPLE 8

This example illustrates another embodiment of this invention. Theprecoat resin dispersion is prepared according to the procedure ofExample 1 using the formulation of Example 2 except that 1% of ahydroxyethylcellulose is used instead of 2% of a polysodium acrylatedispersion.

EXAMPLE 9

This example illustrates another embodiment of this invention. Theprecoat resin dispersion is prepared according to the procedure ofExample 1 using the formulation of Example 2 except that 2% of ahydroxyethylcellulose is used instead of 2% of a polysodium acrylatedispersion.

EXAMPLE 10

This example illustrates another embodiment of this invention. Theprecoat resin dispersion is prepared according to the procedure ofExample 1 using the formulation of Example 2 except that 1% of a sodiumsalt of carboxymethylcellulose (CMC) is used instead of 2% of apolysodium acrylate dispersion.

EXAMPLE 11

This example illustrates another embodiment of this invention. Theprecoat resin dispersion is prepared according to the procedure ofExample 1 using the formulation of Example 2 except that 3% of a CMC isused instead of 2% of a polysodium acrylate dispersion.

EXAMPLE 12

This example illustrates another embodiment of this invention. Theprecoat resin dispersion is prepared according to the procedure ofExample 1 using the formulation of Example 2 except that 2% of a CMC isused instead of 2% of a polysodium acrylate dispersion.

EXAMPLE 13

This example shows the tuft bond strength of finished carpets preparedwith the precoat resin dispersion of this invention and a carboxylatedstyrene-butadiene rubber latex as the backcoat.

Carpet specimens are prepared according to the procedures of ANSI/ASTMD1335-67 using 10 oz./yd.² of the precoat resin dispersion of Example 1as the precoat and then applying 24 oz./yd.² of the carboxylatedstyrene-butadiene rubber latex as the backcoat and, as the control, acarpet specimen prepared in the same manner without the precoat, butbackcoated with 24 oz./yd.² of the carboxylated styrene-butadiene rubberlatex. The carpet test specimens are mounted and tested for tuft bondstrength according to ANSI/ASTM D1335-67. Basically, this test measuresthe amount of force required to separate individual pile yarns from thecarpet. The tuft bond strength of the control carpet test specimen is12-16 lbs.; whereas the carpet test specimen with the precoat resindispersion of this invention is 22-26 lbs.

Other features, advantages and specific embodiments of this inventionwill become apparent to those exercising ordinary skill in the art afterreading the foregoing disclosures. Such specific embodiments are withinthe scope of this invention. Moreover, while specific embodiments of theinvention have been described in considerable detail, it is not limitedthereto, and variations and modifications of those embodiments can beeffected without departing from the spirit and scope of the invention.

What I claim and desire to secure by Letter Patent is:
 1. A carpetcomprising:(a) a primary backing fabric stitched with loops of yarn onthe frontside of the primary backing fabric to form a tufted structure;(b) a precoat resin dispersion coated on the backside of the primarybacking fabric having a solids content from about 63% to about 69%containing(i) from about 93% to about 99% by weight of at least oneresin material selected from the group consisting of hydrocarbon resinsprepared from petroleum refined streams, polyterpene resins and estersof rosin having a Ring and Ball softening point of from about 60° C., toabout 100° C. in an aqueous dispersion having a solids content fromabout 53% to about 58%; (ii) from about 0.5% to about 5%, by weight ofthe total water content of (i), of at least one water-soluble polymerselected from the group consisting of polyacrylates and cellulosederivatives; (iii) from about 0.1% to about 2.0% of at least onecationic polyamide-epichlorohydrin resin, by weight of the total solidsof (i); and (iv) optionally, sufficient water so that the solids contentof the precoat resin dispersion is from about 63% to about 69%; and (c)a carboxylated styrene-butadiene latex applied over the precoat resindispersion.
 2. The precoat resin dispersion of claim 1 wherein (b) (i)is a hydrocarbon resin prepared from petroleum refined streams selectedfrom the group consisting of C₅ -C₉ hydrocarbon resins and C₅hydrocarbon resins.
 3. The precoat resin dispersion of claim 2 wherein(b) (i) is a C₅ -C₉ hydrocarbon resin.
 4. The precoat resin dispersionof claim 2 wherein (b) (i) is a C₅ hydrocarbon resin.
 5. The precoatresin dispersion of claim 1 wherein (b) (i) is an ester of rosin.
 6. Theprecoat resin dispersion of claim 1 wherein (b) (ii) is a polysodiumacrylate.
 7. The precoat resin dispersion of claim 1 wherein (b) (ii) isa cellulose derivative.
 8. The precoat resin dispersion of claim 7wherein the cellulose derivative is selected from the group consistingof carboxymethylcellulose, methylcellulose, hydroxyethylcellulose,hydroxypropylcellulose, methylhydroxyethylcellulose,methylhydroxypropylcellulose, carboxymethylhydroxyethylcellulose,hydroxypropylhydroxyethylcellulose, and hydrophobically modifiedhydroxyethylcellulose.
 9. The precoat resin dispersion of claim 1wherein (b) (iii) has a viscosity at 25° C. of from about 50 cps toabout 325 cps.
 10. A carpet comprising:(a) a primary backing fabricstitched with loops of yarn on the frontside of the primary backingfabric to form a tufted structure; (b) a precoat resin dispersion coatedon the backside of the primary backing fabric having a solids contentfrom about 64% to about 67% containing(i) from about 94% to about 97% byweight of at least one resin material selected from the group consistingof hydrocarbon resins prepared from petroleum refined streams,polyterpene resins and esters of rosin having a Ring and Ball softeningpoint of from about 60° C. to about 100° C. in an aqueous dispersionhaving a solids content from about 54% to about 56%; (ii) from about1.5% to about 2.5%, by weight of the total water content of (i), of atleast one water-soluble polymer selected from the group consisting ofpolyacrylates and cellulose derivatives; (iii) from about 0.5% to about1.5% of at least one cationic polyamide-epichlorohydrin resin, by weightof the total solids of (i); and (iv) optionally, sufficient water sothat the solids content of the precoat resin dispersion is from about64% to about 67%; and (c) a carboxylated styrene-butadiene latex appliedover the precoat resin dispersion.
 11. The precoat resin dispersion ofclaim 10 wherein (b) (i) is a hydrocarbon resin prepared from petroleumrefined streams selected from the group consisting of C₅ -C₉ hydrocarbonresins and C₅ hydrocarbon resins.
 12. The precoat resin dispersion ofclaim 11 wherein (b) (i) is a C₅ -C₉ hydrocarbon resin.
 13. The precoatresin dispersion of claim 11 wherein (b) (i) is a C₅ hydrocarbon resin.14. The precoat resin dispersion of claim 10 wherein (b) (i) is an esterof rosin.
 15. The precoat resin dispersion of claim 10 wherein (b) (ii)is a polysodium acrylate.
 16. The precoat resin dispersion of claim 10wherein (b) (ii) is a cellulose derivative.
 17. The precoat resindispersion of claim 16 wherein the cellulose derivative is selected fromthe group consisting of carboxymethylcellulose, methylcellulose,hydroxyethylcellulose, hydroxypropylcellulose,methylhydroxyethylcellulose, methylhydroxypropylcellulose,carboxymethylhydroxyethylcellulose, hydroxypropylhydroxyethylcellulose,and hydrophobically modified hydroxyethylcellulose.
 18. The precoatresin dispersion of claim 10 wherein (b) (iii) has a viscosity at 25° C.of from about 50 cps to about 325 cps.